Several mosques in the US have received hate-filled letters from California that warn Muslims to either leave the country or face genocide.

Several mosques in the US have received hate-filled letters from California that warn Muslims to either leave the country or face genocide.

These letters, addressed to “the children of Satan”, have been postmarked from the Los Angeles area to mosques throughout California and in Ohio, Michigan, Rhode Island, Indiana, Colorado and Georgia.

The letters appeared to be photocopies of a handwritten note referring to Muslims as “vile and filthy people” and saying that President-elect Donald Trump would do to Muslims what Hitler did to Jews.

The Council on American-Islamic Relations has asked the FBI to investigate.

The FBI said the threats, while inflammatory and awful, do not pose a threat specific enough to investigate at this point, but they're monitoring the situation and urged anyone to report such incidents.

Police in Providence, Rhode Island, said they would increase patrols after one of the letters was received at Masjid Al-Kareem.

Faissal Elansari of the Islamic Centre of Rhode Island said he feels a wave of hate at his doorstep, WPRI-TV reported.

Envelopes have had a return address in the city the letter was sent often 331 Oak St. but are postmarked in Los Angeles or Santa Clarita, a suburb about 30 miles north.

The name is bogus, said Sgt. Mike Abdeen of the Los Angeles Sheriff's Department, which is assisting LAPD.

Letters have been received at six mosques in California, including Los Angeles, Fresno and San Jose, according to police and Islamic groups. Elsewhere, they have also turned up at mosques in Denver, Ann Arbor, Michigan, Savannah, Georgia, and a school affiliated with an Indianapolis mosque.

Trump's spokespeople have not responded to a request for comment. The president-elect told “60 Minutes” that if his supporters were harassing others, they should “stop it.”